Semiconductor devices and fabricating methods thereof

ABSTRACT

Provided is a semiconductor device and a fabricating method thereof. The semiconductor device includes a first trench having a first depth to define a fin, a second trench formed directly adjacent the first trench having a second depth that is greater than the first depth, a field insulation layer filling a portion of the first trench and a portion of the second trench, and a protrusion structure protruding from a bottom of the first trench and being lower than a surface of the field insulation layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 15/708,512, filed Sep. 19, 2017, which iscontinuation application of U.S. patent application Ser. No. 14/976,082,filed Dec. 21, 2015 (now U.S. Pat. No. 9,768,169) which claims priorityto U.S. Provisional Patent Application No. 62/104,478, filed Jan. 16,2015, which claims priority from Korean Patent Application No.10-2014-0194004 filed Dec. 30, 2014, the contents of which are herebyincorporated herein as if set forth in their entireties.

BACKGROUND

As one scaling technique for increasing the density of integratedcircuit devices, a multi-gate transistor has been proposed, in which afin- or nanowire-shaped silicon body is formed on a substrate and a gateis then formed on a surface of the silicon body.

Since the multi-gate transistor uses a three-dimensional (3D) channel,scaling of the multi-gate transistor is easily achieved. In addition,current controlling capability can be improved even without increasing agate length of the multi-gate transistor. Further, a short channeleffect (SCE), in which an electric potential of a channel region isaffected by a drain voltage, can be effectively suppressed.

SUMMARY

The present inventive concept provides semiconductor devices, which canminimize a development burden.

The present inventive concept also provides fabricating methods of asemiconductor device, which can minimize a development burden.

These and other objects of the present inventive concept will bedescribed in or be apparent from the following description of someembodiments thereof.

According to some embodiments of the present inventive concept, there isprovided a semiconductor device including a first trench having a firstdepth to define a fin, a second trench formed directly adjacent thefirst trench having a second depth greater than the first depth, a fieldinsulation layer filling a portion of the first trench and a portion ofthe second trench, and a protrusion structure protruding from a bottomof the first trench and being lower than a surface of the fieldinsulation layer.

In some embodiments, there is provided a semiconductor device includinga first trench having a first depth to define a first active region anda second active region separated from each other, a second trenchdefining a first fin in the first active region and having a seconddepth smaller than the first depth, a third trench defining a second finin the second active region and having a third depth smaller than thefirst depth, a field insulation layer filling a portion of the firsttrench, a portion of the second trench and a portion of the thirdtrench, and a first protrusion structure protruding from a bottom of thesecond trench and being lower than a surface of the field insulationlayer.

According to some embodiments of the present inventive concept, there isprovided a semiconductor device including a protrusion structure thathas a first inclined surface and a second inclined surface, a firsttrench connected to the first inclined surface and defining a fin, and asecond trench connected to the second inclined surface, wherein aninclination angle of a sidewall the second trench is equal to aninclination angle of the second inclined surface, and a height of theprotrusion structure is smaller than a height of the fin.

According to some embodiments of the present inventive concept, thereare provided fabricating methods of a semiconductor device includingforming a plurality of fins by forming a plurality of first trencheshaving a first depth, defining an active region by forming a secondtrench having a second depth greater than the first depth, the firsttrench and the second trench partially overlapping each other so that aprotrusion structure is formed at a boundary between the first trenchand the second trench, and forming a field insulation layer filling aportion of the first trench and a portion of the second trench.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present inventiveconcept will become more apparent by describing in detail someembodiments thereof with reference to the attached drawings in which:

FIG. 1 is a layout view illustrating a semiconductor device according toa first embodiment of the present inventive concept;

FIG. 2 is a cross-sectional view taken along the line A-A of FIG. 1;

FIG. 3 is a cross-sectional view taken along the line B-B of FIG. 1;

FIG. 4 is a cross-sectional view taken along the line C-C of FIG. 1;

FIG. 5 is a cross-sectional view illustrating a semiconductor deviceaccording to a second embodiment of the present inventive concept;

FIG. 6 is a cross-sectional view illustrating a semiconductor deviceaccording to a third embodiment of the present inventive concept;

FIG. 7 is a cross-sectional view illustrating a semiconductor deviceaccording to a fourth embodiment of the present inventive concept;

FIG. 8 is a cross-sectional view illustrating a semiconductor deviceaccording to a fifth embodiment of the present inventive concept;

FIG. 9 is a cross-sectional view illustrating a semiconductor deviceaccording to a sixth embodiment of the present inventive concept;

FIG. 10 is a cross-sectional view taken along the line D-D of FIG. 9;

FIG. 11 is a cross-sectional view illustrating a semiconductor deviceaccording to a seventh embodiment of the present inventive concept;

FIG. 12 is a cross-sectional view illustrating a semiconductor deviceaccording to an eighth embodiment of the present inventive concept;

FIGS. 13 to 16 are diagrams illustrating intermediate process steps of afabricating method for the semiconductor device according to the firstembodiment of the present inventive concept;

FIG. 17 is a block diagram of a memory card including semiconductordevices according to some embodiments of the present inventive concept;

FIG. 18 is a block diagram of an information processing system includingsemiconductor devices according to some embodiments of the presentinventive concept; and

FIG. 19 is a block diagram of an electronic device includingsemiconductor devices according to some embodiments of the presentinventive concept.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments will be described in detail with reference to theaccompanying drawings. The inventive concept, however, may be embodiedin various different forms, and should not be construed as being limitedonly to the illustrated embodiments. Rather, these embodiments areprovided as examples so that this disclosure will be thorough andcomplete, and will fully convey the concept of the inventive concept tothose skilled in the art. Accordingly, known processes, elements, andtechniques are not described with respect to some of the embodiments ofthe inventive concept. Unless otherwise noted, like reference numeralsdenote like elements throughout the attached drawings and writtendescription, and thus descriptions will not be repeated. In thedrawings, the sizes and relative sizes of layers and regions may beexaggerated for clarity.

It will be understood that, although the terms “first”, “second”,“third”, etc., may be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are only used to distinguish one element, component, region,layer or section from another region, layer or section. Thus, a firstelement, component, region, layer or section discussed below could betermed a second element, component, region, layer or section withoutdeparting from the teachings of the inventive concept.

Spatially relative terms, such as “beneath”, “below”, “lower”, “under”,“above”, “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation in addition tothe orientation depicted in the figures. For example, if the device inthe figures is turned over, elements described as “below” or “beneath”or “under” other elements or features would then be oriented “above” theother elements or features. Thus, the exemplary terms “below” and“under” can encompass both an orientation of above and below. The devicemay be otherwise oriented (rotated 90 degrees or at other orientations)and the spatially relative descriptors used herein interpretedaccordingly. In addition, it will also be understood that when a layeris referred to as being “between” two layers, it can be the only layerbetween the two layers, or one or more intervening layers may also bepresent.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the inventiveconcept. As used herein, the singular forms “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, integers, steps, operations,elements, components, and/or groups thereof. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items. Also, the term “exemplary” is intended to referto an example or illustration.

It will be understood that when an element or layer is referred to asbeing “on”, “connected to”, “coupled to”, or “adjacent to” anotherelement or layer, it can be directly on, connected, coupled, or adjacentto the other element or layer, or intervening elements or layers may bepresent. In contrast, when an element is referred to as being “directlyon,” “directly connected to”, “directly coupled to”, or “immediatelyadjacent to” another element or layer, there are no intervening elementsor layers present.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this inventive concept belongs. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and/orthe present specification and will not be interpreted in an idealized oroverly formal sense unless expressly so defined herein.

FIG. 1 is a layout view illustrating a semiconductor device according toa first embodiment of the present inventive concept, FIG. 2 is across-sectional view taken along the line A-A of FIG. 1, FIG. 3 is across-sectional view taken along the line B-B of FIG. 1, and FIG. 4 is across-sectional view taken along the line C-C of FIG. 1.

The semiconductor device according to the first embodiment of thepresent inventive concept will now be described with regard to a casewhere it is an N-type fin transistor, but aspects of the presentinventive concept are not limited thereto.

Referring first to FIGS. 1 to 3, the semiconductor device according tothe first embodiment of the present inventive concept is formed in anactive region ACT1 of a substrate 100. The substrate 100 may include oneor more semiconductor material selected from the group consisting of Si,Ge, SiGe, GaP, GaAs, SiC, SiGeC, InAs and InP. Some embodiments providethat the substrate 100 may be, for example, a silicon on insulator (SOI)substrate.

A fin F1 may extend in a first direction X. The fin F1 may be a portionof the substrate 100 and may include an epitaxial layer grown from thesubstrate 100.

In FIG. 1, the fin F1 having a rectangular shape is illustrated, butaspects of the present inventive concept are not limited thereto.Corners of the fin F1 may be eroded to be slightly inclined, that is,the fin F1 may have a chamfered shape. In addition, when the fin F1 isrectangular, it may include long sides and short sides.

As shown in FIG. 1, a single fin F1 may be formed in the active regionACT1 (that is, a single fin structure). That is to say, thesemiconductor device according to the first embodiment of the presentinventive concept may be a fin type transistor using a single fin F1.Unlike in the illustrated embodiment, two or more fins F1 may be formedin the active region ACT1 (that is, a dual fin structure or a multi finstructure).

A metal gate 199 may be formed on the fin F1 so as to intersect the finF1. That is to say, the metal gate 199 may extend in a second directionY. The metal gate 199 may include a lower metal layer 132, an N typework function control layer 170, a wetting layer 181, and a gap filllayer 190. The metal gate 199 may be formed by a replacement process.

The interlayer insulation layer 110 may be formed on the substrate 100and may include a trench 112. The interlayer insulation layer 110 may beformed by stacking two or more insulation layers. As shown, sidewalls ofthe trench 112 may make contact with a spacer 120 and a bottom surfaceof the trench 112 may make contact with the substrate 100.

The spacer 120 may include at least one of a nitride layer and anoxynitride layer.

An interface layer 135 may be formed in the trench 112. As shown, theinterface layer 135 may be formed on a bottom surface of the trench 112by an oxidation process. In addition, unlike in the illustratedembodiment, the interface layer 135 may be conformally formed along thesidewalls and bottom surface of the trench 112 by a deposition process.The deposition process may include, for example, chemical vapordeposition (CVD), and/or atomic layer deposition (ALD), but not limitedthereto. The interface layer 135 may be a silicon oxide layer (e.g.,HTO), but not limited thereto. The interface layer 135 may be formed toa thickness of, for example, about 50 Å or less (in a range of about 5 Åto about 50 Å). For example, the interface layer 135 may be formed to athickness of 10 Å. The interface layer 135 may be used to improveoperating characteristics (that is, to increase a breakdown voltage) ofa high-voltage transistor.

A dielectric layer 130 may be formed on the interface layer 135conformally along the sidewalls and bottom surface of the trench 112.The dielectric layer 130 and the interface layer 135 may be disposed tomake contact with each other. The dielectric layer 130 may include ahigh-k material having a higher dielectric constant than silicon oxide.The dielectric layer 130 may include, for example, a material selectedfrom the group consisting of HfO₂, ZrO₂, Ta₂O₅, TiO₂, SrTiO₃ and(Ba,Sr)TiO₃. The dielectric layer 130 may be formed to an appropriatethickness according to the kind of device to be formed. For example,when the dielectric layer 130 includes HfO₂, it may be formed to athickness of about 50 Å or less (that is, in a range of about 5 Å toabout 50 Å).

The lower metal layer 132 may be formed on the dielectric layer 130conformally along the sidewalls and bottom surface of the trench 112.The lower metal layer 132 may include, for example, at least one of TiNand TaN. For example, the lower metal layer 132 may be a stacked layerof TiN and TaN. In this case, a TiN layer is formed to make contact withthe dielectric layer 130 and a TaN layer may be formed on the TiN layerso as to make contact with the TiN layer. The TiN layer may protect thedielectric layer 130 and the TaN layer may be used as an etch stop layerwhen a portion of the N type work function control layer 170 is removed.

The N type work function control layer 170 may be formed on the lowermetal layer 132 in the trench 112. As shown, the N type work functioncontrol layer 170 may also conformally formed along the sidewalls andbottom surface of the trench 112. The N type work function control layer170 may control a work function of an N type transistor, therebyadjusting operating characteristics of the N type transistor. The N typework function control layer 170 may include a material selected from thegroup consisting of TiAl, TiAlC, TiAlN, TaC, TiC, and HfSi. For example,the N type work function control layer 170 may be a TiAlC.

The wetting layer 181 may be formed on the N type work function controllayer 170 in the trench 112. The wetting layer 181 may include at leastone of TiN and Ti. In some embodiments, the wetting layer 181 mayinclude a TiN layer and a T1 layer sequentially stacked. For example,when the gap fill layer 190 includes aluminum (Al), the wetting layer181 may be formed of a single layer of T1 or TiN. When the gap filllayer 190 includes tungsten (W), the wetting layer 181 may be formed ofa single layer of TiN. The wetting layer 181 may be formed to athickness in a range between about 10 Å and 100 Å (for example, 70 Å).

Meanwhile, referring to FIGS. 1 and 4, as described above, the fin F1may be defined by a first trench T1 having a first depth D1, the activeregion ACT1 may be defined by a second depth (D1+D2) that is greaterthan the first depth D1. The first trench T1 may be a shallow trench andthe second trench T2 may be a deep trench.

In some embodiments, the first trench T1 and the second trench T2 may bedisposed to be directly adjacent one another. The phrase “directlyadjacent” used herein may mean that another trench having a first depth(i.e., a shallow trench) does not intervene between the first trench T1and the second trench T2.

A field insulation layer 105 is formed to fill a portion of the firsttrench T1 and a portion of the second trench T2.

Protrusion structures PRT1 and PRT2 may protrude from a bottom of thefirst trench T1 and may be formed to be lower than a surface of thefield insulation layer 105. As shown, the protrusion structures PRT1 andPRT2 may be positioned at a boundary between the first trench T1 and thesecond trench T2.

For example, after forming a plurality of fins by forming the firsttrench T1 having the first depth D1 (see FIGS. 13 and 14), the secondtrench T2 having the second depth (D1+D2) greater than the first depthD1 is formed, thereby defining the active region ACT1 (see FIGS. 15 and16). Here, when the second trench T2 is formed, among the plurality offins (e.g., 3 fins), only a target number of fins (e.g., one fin) areleft. That is to say, when the second trench T2 is formed, among theplurality of fins (e.g., 3 fins), a number of fins (e.g., 2 fins) areremoved. If a mask for forming the first trench T1 and a mask forforming the second trench T2 are misaligned, the number of fins (e.g., 2fins) may not be completely removed when the second trench T2 is formed,but traces may remain. The traces may become the protrusion structuresPRT1 and PRT2.

Here, if the protrusion structures PRT1 and PRT2 have considerably largesizes, the large sizes may cause failures in a subsequent process.However, in order to completely remove the protrusion structures PRT1and PRT2, processing conditions may be quite strictly managed. In thiscase, however, a development burden may be unavoidably incurred.Therefore, the protrusion structures PRT1 and PRT2 may be managed so asto have appropriate sizes, thereby minimizing the development burdenwhile increasing the yield. For example, the protrusion structures PRT1and PRT2 may be managed such that their height H1 is smaller than aheight H10 of the fin F1 and the protrusion structures PRT1 and PRT2 arelower than a surface of the field insulation layer 105. If tips of theprotrusion structures PRT1 and PRT2 protrude higher than the surface ofthe field insulation layer 105, a processing failure (e.g., a short) mayoccur in a subsequent replacement process).

The protrusion structures PRT1 and PRT2 include a first inclined surfaceS1 disposed at a side of the first trench T1 and a second inclinedsurface S2 disposed at a side of the second trench T2. The firstinclined surface S1 may have a first inclination angle and the secondinclined surface S2 may have a second inclination angle that isdifferent from the first inclination angle. As shown, the secondinclined surface S2 having the second inclination angle may be steeperthan the first inclined surface S1 having the first inclination angle.The first inclined surface S1 is connected to the first trench T1 andthe second inclined surface S2 is connected to the second trench T2. Theinclination angle of the second inclined surface S2 is equal to aninclination angle of a sidewall S3 of the second trench T2. That is tosay, the second inclined surface S2 and the sidewall S3 of the secondtrench T2 may be disposed on the same line.

Meanwhile, the protrusion structures PRT1 and PRT2 may be disposed atopposite sides of the active region ACT1 in view of the fin F1. Inaddition, as shown, the first protrusion structure PRT1 and the secondprotrusion structure PRT2 may be symmetrically disposed with respect toeach other in view of the fin F1.

In addition, the protrusion structures PRT1 and PRT2 may extendlengthwise in a direction (X) in which the fin F1 extends. In addition,as shown in FIGS. 1 and 3, the metal gate 199 may be formed to intersectthe fin F1 and the protrusion structures PRT1 and PRT2.

FIG. 5 is a cross-sectional view illustrating a semiconductor deviceaccording to a second embodiment of the present inventive concept. Forthe sake of brevity and convenient explanation, the followingdescription will focus on differences between the present embodiment andthe previous embodiment shown in FIGS. 1 to 4.

Referring to FIG. 5, in the semiconductor device according to the secondembodiment of the present inventive concept, a protrusion structure PRT1may be disposed at only one side of the active region ACT1 in view of afin F1.

Likewise, the protrusion structure PRT1 may have a height H1 and theheight may be lower than a surface of a field insulation layer 105. Theprotrusion structure PRT1 includes a first inclined surface S1 disposedat a side of a first trench T1 and a second inclined surface S2 disposedat a side of a second trench T2. The first inclined surface S1 may havea first inclination angle and the second inclined surface S2 may have asecond inclination angle different from the first inclination angle. Asshown, the second inclined surface S2 having the second inclinationangle may be steeper than the first inclined surface S1 having the firstinclination angle. The first inclined surface S1 is connected to thefirst trench T1 and the second inclined surface S2 is connected to thesecond trench T2.

FIG. 6 is a cross-sectional view illustrating a semiconductor deviceaccording to a third embodiment of the present inventive concept. Forthe sake of brevity and convenient explanation, the followingdescription will focus on differences between the present embodiment andthe previous embodiment shown in FIGS. 1 to 4.

Referring to FIG. 6, in the semiconductor device according to the thirdembodiment of the present inventive concept, protrusion structures PRT1and PRT2 may be asymmetrically disposed with respect to each other inview of the fin F1.

The first protrusion structure PRT1 and the second protrusion structurePRT2 may have different sizes. That is to say, the height H1 of theprotrusion structure PRT1 and the height H2 of the second protrusionstructure PRT2 may be different from each other. As shown, the firstprotrusion structure PRT1 may be larger than the second protrusionstructure PRT2 in size, and the height H1 of the first protrusionstructure PRT1 may be greater than the height H2 of the secondprotrusion structure PRT2.

FIGS. 7 and 8 are cross-sectional views illustrating semiconductordevices according to fourth and fifth embodiments of the presentinventive concept. For the sake of brevity and convenient explanation,the following description will focus on differences between the presentembodiment and the previous embodiment shown in FIGS. 1 to 4.

As shown in FIG. 7, the semiconductor device according to the fourthembodiment of the present inventive concept may be a fin type transistorusing two fins F1 and F2 (i.e., a dual fin structure). That is to say,the two fins F1 and F2 may be formed in a first active region ACT1.

Here, a third trench T3 having a third depth may be disposed between thefin F1 and the fin F2. The third trench T3 may be formed at the samewith the first trench T1. In addition, the third depth of the thirdtrench T3 and the first depth of the first trench T1 may be equal toeach other.

As shown in FIG. 8, the semiconductor device according to the fifthembodiment of the present inventive concept may be a fin type transistorusing three or more fins F1 to F7 (i.e., a multi fin structure). That isto say, three or more fins F1 to F7 may be formed in a first activeregion ACT1.

As shown, a first protrusion structure PRT1 may be formed between afirst trench T1 disposed at a side of a fin F7 (i.e., a fin disposed atone end) and a second trench T2 and a second protrusion structure PRT2may be formed between the first trench T1 disposed at a side of a fin F1(i.e., a fin disposed at the other end) and the second trench T2.

Here, third trench T3 each having a third depth may be disposed betweeneach adjacent ones of the fins F1˜F7. The third trenches T3 may beformed at the same time with the first trench T1. In addition, the thirddepth of the third trench T3 and the first depth of the first trench T1may be equal to each other.

FIG. 9 is a cross-sectional view illustrating a semiconductor deviceaccording to a sixth embodiment of the present inventive concept andFIG. 10 is a cross-sectional view taken along the line D-D of FIG. 9.For the sake of brevity and convenient explanation, the followingdescription will focus on differences between the present embodiment andthe previous embodiment shown in FIGS. 1 to 4.

Referring to FIGS. 9 and 10, the semiconductor device according to thesixth embodiment of the present inventive concept includes a firstactive region ACT1 and a second active region ACT2 separated from eachother. A fin F1 is formed in the first active region ACT1 and a fin F8is formed in the second active region ACT2.

The fins F1 and F8 may extend lengthwise in a first direction X. Thefins F1 and F8 may be portions of a substrate 100 and may includeepitaxial layers grown from the substrate 100.

Here, the fin F1 may be defined by a first trench T1 having a firstdepth D1 and the fin F8 may be defined by a fourth trench T4 having athird depth D3. The first trench T1 and the fourth trench T4 may beformed at the same time. In addition, the first depth D1 and the thirddepth D3 may be equal to each other.

Meanwhile, the first and second active regions ACT1 and ACT2 may bedefined by a second trench T2 having a second depth (D1+D2) greater thanthe first depth D1 or the third depth D3.

As shown, one fin F1, F8 formed in the first, second active region ACT1,ACT2 is illustrated, but aspects of the present inventive concept arenot limited thereto. That is to say, two or more fins may be formed ineach of the active regions ACT1 and ACT2.

A metal gate 199 may be formed on the fin F1 so as to intersect the finF1. The metal gate 199 may extend in a second direction Y. In addition,a metal gate 299 may be formed on the fin F2 so as to intersect the finF2. The metal gate 299 may extend in the second direction Y.

The two metal gates 199 and 299 may be different gates or may beconnected to each other.

A first protrusion structure PRT1 may protrude from a bottom surface ofa first trench T1 and may be lower than the surface of the fieldinsulation layer 105. The first protrusion structure PRT1 may bepositioned at a boundary between the first trench T1 and the secondtrench T2.

The first protrusion structure PRT1 may include a first inclined surfaceS1 disposed at a side of the first trench T1 and a second inclinedsurface S2 disposed at a side of the second trench T2. The inclinedsurface S1 may have a first inclination angle and the inclined surfaceS2 may have a second inclination angle that is different from the firstinclination angle. As shown, the inclined surface S1 has the firstinclination angle and the inclined surface S2 has the second inclinationangle.

In addition, a third protrusion structure PRT3 may protrude from abottom surface of a fourth trench T4 and may be lower than the surfaceof the field insulation layer 105. The third protrusion structure PRT3may be positioned at a boundary between the fourth trench T4 and thesecond trench T2.

The third protrusion structure PRT3 may include an inclined surface S11disposed at a side of the fourth trench T4 and an inclined surface S12disposed at a side of the second trench T2. The inclined surface S11 mayhave an eleventh inclination angle and the inclined surface S12 may havea twelfth inclination angle that is different from the eleventhinclination angle. As shown, the inclined surface S11 has an eleventhinclination angle and the inclined surface S12 having the twelfthinclination angle may be steeper than the inclined surface S11 havingthe eleventh inclination angle. Some embodiments provide that the firstinclination angle and the second inclination angle may be steeper thanthe inclined surface S11 having the eleventh inclination angle.

As shown, the first protrusion structure PRT1 and the third protrusionstructure PRT3 may be symmetrically disposed with respect to each otherin view of the second trench T2. In addition, a height H1 of theprotrusion structure PRT1 may be different from a height H3 of the thirdprotrusion structure PRT3 may be equal to each other.

In addition, the fin F1 may extend lengthwise in a first direction X.The fin F1 may be shaped of a rectangle having long sides and shortsides. Likewise, the fin F8 may extend lengthwise in the first directionX. The fin F8 may be shaped of a rectangle having long sides and shortsides. The long sides of the fin F1 and the fin F8 may be disposed toface each other. The protrusion structures PRT1 and PRT3 may belengthwise formed along the long sides of the fin F1 and the fin F8.

FIG. 11 is a cross-sectional view illustrating a semiconductor deviceaccording to a seventh embodiment of the present inventive concept. Forthe sake of brevity and convenient explanation, the followingdescription will focus on differences between the present embodiment andthe previous embodiment shown in FIGS. 9 and 10.

Referring to FIG. 11, in the semiconductor device according to theseventh embodiment of the present inventive concept, a protrusionstructure PRT1 may be disposed at only one side of a second trench T2.That is to say, the protrusion structure PRT1 may be positioned only ata boundary between a first trench T1 and the second trench T2 but maynot be positioned at a boundary between the second trench T2 and afourth trench T4.

FIG. 12 is a cross-sectional view illustrating a semiconductor deviceaccording to an eighth embodiment of the present inventive concept. Forthe sake of brevity and convenient explanation, the followingdescription will focus on differences between the present embodiment andthe previous embodiment shown in FIGS. 9 and 10.

Referring to FIG. 12, in the semiconductor device according to theeighth embodiment of the present inventive concept, the protrusionstructures PRT1 and PRT3 may be disposed at opposite sides of a secondtrench T2. However, the protrusion structures PRT1 and PRT3 may beasymmetrically disposed with respect to each other in view of the secondtrench T2. In other words, the protrusion structures PRT1 and PRT3 mayhave different sizes. For example, a height H1 of the protrusionstructure PRT1 and a height H4 of the protrusion structure PRT3 may bedifferent from each other.

Hereinafter, a fabricating method for the semiconductor device accordingto the first embodiment of the present inventive concept will bedescribed with reference to FIGS. 13 to 16 with FIGS. 1 to 4.

FIGS. 13 and 15 are diagrams illustrating intermediate process steps ofa fabricating method for the semiconductor device according to the firstembodiment of the present inventive concept, and FIGS. 14 and 16 arecross-sectional views taken along the line C-C of FIGS. 13 and 15.

First, referring to FIGS. 13 and 14, a plurality of fins F1, F11 and F12are formed on a substrate 100. The fins F1, F11 and F12 may extendlengthwise in a first direction X. A mask pattern is formed on thesubstrate 100 and a portion of the substrate 100 is etched using themask pattern. That is to say, the plurality of fins F1, F11 and F12 areformed by forming a first trench T1 having a first depth D1 on thesubstrate 100. The fins F1, F11 and F12 may be disposed such that longsides thereof face each other.

Next, referring to FIGS. 15 and 16, a second trench T2 having a seconddepth (D1+D2) greater than the first depth D1 is formed to define anactive region ACT1. Some fins F11 and F12 among the plurality of finsF1, F11 and F12 are removed by forming the second trench T2. That is tosay, portions of the first trench T1 and the second trench T2 mayoverlap each other. In such a manner, protrusion structures PRT1 andPRT2 may be formed at a boundary between the first trench T1 and thesecond trench T2.

The protrusion structures PRT1 and PRT2 may have various shapesaccording to the extent of alignment between the first trench T1 and thesecond trench T2. That is to say, the protrusion structures PRT1 andPRT2 may be symmetrically disposed with respect to each other (see FIGS.4 and 16). In some embodiments, the protrusion structure PRT1 may beformed only at one side of the active region ACT1 (see FIG. 5), or theprotrusion structures PRT1 and PRT2 may be formed at opposite sides ofthe active region ACT1 to be symmetrical with respect to each other inview of the fin F1 (see FIG. 6).

Referring again to FIGS. 1 to 4, the metal gate 199 is formed tointersect the fin F1. In detail, a poly gate is formed to intersect thefin F1 and the interlayer insulation layer 110 is then formed tosufficiently cover the fin F1 and the poly gate. A polarization processis performed to expose a top surface of the poly gate. Next, the exposedpoly gate is removed to form the trench 112. The dielectric layer 130and the metal gate 199 are formed in the trench 112.

Those skilled in the art can fully analogize fabricating methods of thesemiconductor devices according to the second to eighth embodimentsbased on the aforementioned fabricating method of the semiconductordevices according to the first embodiment of the present inventiveconcept.

FIG. 17 is a block diagram illustrating an example memory card includingsemiconductor devices according to some embodiments of the presentinventive concept.

Referring to FIG. 17, a memory 1210 including semiconductor devicesaccording to various embodiments of the present inventive concept can beemployed to the memory card 1200. The memory card 1200 according to thepresent inventive concept includes a memory controller 1220 controllingdata exchange between a host and the memory 1210.

A static random access memory (SRAM) 1221 is used as a working memory ofa processing unit 1222. A host interface 1223 includes a data exchangeprotocol of the host 1230 connected to the memory card 1200. An errorcorrection block 1224 detects and corrects an error included in dataread from the memory 1210. A memory interface 1225 interfaces with thememory 1210 according to the present inventive concept. A centralprocessing unit 1222 performs an overall controlling operation for dataexchange of the memory controller 1220.

FIG. 18 is a block diagram illustrating an example informationprocessing system having a semiconductor device according to someembodiments of the present inventive concept mounted therein.

Referring to FIG. 18, an information processing system 1300 may includea memory system 1310 including semiconductor devices according tovarious embodiments of the present inventive concept. The informationprocessing system 1300 according to the present inventive conceptincludes a memory system 1310, a modem 1320, a central processing unit(CPU) 1330, a random access memory (RAM) 1340, and a user interface1350, which are electrically connected to a system bus 1360,respectively. The memory system 1310 may include a memory 1311 and amemory controller 1312 and may have substantially the same configurationas the memory card 1200 shown in FIG. 12. The memory system 1310 maystore data processed by the CPU 1330 and/or data received from anexternal device.

The information processing unit 1300 may be applied to a memory card, asolid state disk (SSD), a camera image processor (CIS) and other variousan application chipsets. For example, the information processing unit1300 may be configured to employ a solid state disk (SSD) and, in thiscase, it can stably process large-capacity data in a stable, reliablemanner.

FIG. 19 is a block diagram of an electronic device includingsemiconductor devices according to some embodiments of the presentinventive concept.

Referring to FIG. 19, the electronic device 1400 may includesemiconductor devices according to some embodiments of the presentinventive concept. The electronic device 1400 may be applied to awireless communication device (for example, a personal digital assistant(PDA), a notebook computer, a portable computer, a web tablet, awireless phone, and/or a wireless digital music player) or any type ofelectronic device capable of transmitting and/or receiving informationin a wireless environment.

The electronic device 1400 may include a controller 1410, aninput/output device (I/O) 1420, a memory 1430, and a wireless interface1440. Here, the memory 1430 may include semiconductor devices accordingto various embodiments of the present inventive concept. The controller1410 may include a microprocessor, a digital signal processor, and aprocessor capable of performing functions similar to these components.The memory 1430 may be used to store commands processed by thecontroller 1410 (or user data). The wireless interface 1440 may be usedto exchange data through a wireless data network. The wireless interface1440 may include an antenna and/or a wired/wireless transceiver. Forexample, the electronic device 1400 may use a third generationcommunication system protocol, such as CDMA, GSM, NADC, E-TDMA, WCDMA,CDMA2000, or the like.

While the present inventive concept has been particularly shown anddescribed with reference to example embodiments thereof, it will beunderstood by those of ordinary skill in the art that various changes inform and details may be made therein without departing from the spiritand scope of the present inventive concept as defined by the followingclaims. It is therefore desired that the present embodiments beconsidered in all respects as illustrative and not restrictive,reference being made to the appended claims rather than the foregoingdescription to indicate the scope of the inventive concept.

What is claimed is:
 1. A semiconductor device comprising: a first trench having a first depth in a vertical direction that defines a fin; a second trench that is directly adjacent to the first trench and that has a second depth that is greater than the first depth; a field insulation layer that fills a portion of the first trench and a portion of the second trench; a protrusion structure that is positioned at a side of a bottom of the first trench that is connected to a bottom of the second trench and that is covered by the field insulation layer; and a gate crossing over the fin and the protrusion structure, wherein the protrusion structure has a first surface that is at a side of the first trench and a second surface that is at a side of the second trench, and wherein the first surface has a first inclination angle and the second surface has a second inclination angle that is different from the first inclination angle.
 2. The semiconductor device of claim 1, wherein the fin extends lengthwise in a first direction.
 3. The semiconductor device of claim 1, wherein the second inclination angle is greater than the first inclination angle.
 4. The semiconductor device of claim 1, wherein the second trench defines an active region.
 5. The semiconductor device of claim 4, wherein the protrusion structure comprises a first protrusion structure, wherein the semiconductor device further comprises a second protrusion structure, and wherein the first protrusion structure is on a first side of the active region relative to the fin and the second protrusion structure is at an opposing second side of the active region relative to the fin.
 6. The semiconductor device of claim 5, wherein the first protrusion structure and the second protrusion structure have different heights.
 7. A semiconductor device comprising: a protrusion structure that includes a first surface and a second surface; a first trench that defines a first fin and that has a first depth in a vertical direction, a bottom of the first trench being connected to the first surface; a second trench that has a second depth that is greater than the first depth, a bottom of the second trench being connected to the second surface; and a field insulation layer that fills the first trench and the second trench, and that covers the protrusion structure; and a gate on the field insulation layer, wherein the gate crosses over the first fin and the protrusion structure, and wherein the first surface has a first inclination angle and the second surface has a second inclination angle that is different from the first inclination angle.
 8. The semiconductor device of claim 7, wherein the second inclination angle is greater than the first inclination angle.
 9. The semiconductor device of claim 7, wherein the first surface is directly connected to the second surface.
 10. The semiconductor device of claim 7, further comprising a second fin, wherein the second trench is disposed between the protrusion structure and the second fin.
 11. The semiconductor device of claim 7, wherein the first fin extends lengthwise in a first direction.
 12. A semiconductor device comprising: a protrusion structure that includes a first surface and a second surface; a first trench that defines a first fin, a bottom of the first trench being positioned at a side of the protrusion structure; a second trench that is connected to the second surface; and a field insulation layer that fills the first trench and the second trench, and that covers the protrusion structure; and a gate on the field insulation layer, wherein the gate crosses over the first fin and the protrusion structure, and wherein a first height of the protrusion structure from a bottom of the second trench is greater than a second height of the protrusion structure from the bottom of the first trench.
 13. The semiconductor device of claim 12, wherein the first surface has a first inclination angle and the second surface has a second inclination angle that is different from the first inclination angle.
 14. The semiconductor device of claim 13, wherein the second inclination angle is greater than the first inclination angle.
 15. The semiconductor device of claim 12, wherein the first surface is directly connected to the second surface.
 16. The semiconductor device of claim 12, further comprising a second fin, wherein the second trench is disposed between the protrusion structure and the second fin.
 17. The semiconductor device of claim 12, wherein the first fin extends lengthwise in a first direction. 